The present disclosure relates generally to welding and cutting power supplies, and more particularly, to a method and system for controlling a dual circuit inverter power supply.
Power supply circuits typically convert AC power to an output suitable for welding or cutting operations. The output power is provided at an appropriate voltage and/or current level and may be controlled and regulated according to the process requirements. Many industrial welding and cutting processes have dynamic load voltage and current requirements that cannot be met by a static power supply output. For instance, initiation of an arc, electrode characteristics, length of an active arc, operator technique, and so forth may all contribute to transient voltage requirements. Oftentimes, these dynamic requirements, which are above the average load conditions, are of short duration (˜1 millisecond—a few seconds) and comprise only a small part of the overall welding or cutting time. Accordingly, the power supply must be capable of providing both average and dynamic load requirements.
Single or double forward converter circuits are currently used to fulfill these dual requirements. The average load requirements typically determine the thermal design of the power supply circuits, dictating the size and rating of components such as transformers, heat sinks, power devices, cooling fans and so forth. However, for welding and cutting power supplies to accommodate short dynamic loads, components capable of handling the short but extreme requirements traditionally must be chosen. This generally results in a circuit with oversized components or a lack of efficiency when the power supply is operating at average conditions. Accordingly, there exists a need for circuits that can better handle both static and dynamic load requirements without the inefficiencies of traditional designs.